[3] Facing mostly sub-par Zhili forces, the Second Army rapidly advanced and managed to capture all important strategic cities of Rehe Province between 15 September and 9 October, namely Kailu, Chaoyang, Fuxin, Jianping, and Chifeng.

[4] The daring offensive of Zhang and Li's combined forces against the extremely significant Lengkou pass was "probably the single most important engagement" of the war.

[6] This came not to pass, however, as Feng Yuxiang launched the Beijing Coup against the Zhili clique's official leader and President of the Republic of China, Cao Kun, on 23 October.

These massive defeats effectively caused the Zhili clique's military to collapse, and over the following days a disorganized retreat began which quickly turned into a rout.

[8] On 11 December 1924,[9] Li Jinglin was officially appointed civil and military governor of Zhili province[10] and set up a "repressive and predatory" regime.

A close associate of Li Jinglin (who was a renowned martial artist in his own right) since 1921, he was appointed in 1925 to lead a battalion of six hundred men in the Zhili Army.

At the time, Zhang Zuolin was facing a rebellion of one of his generals, Guo Songling,[14] so that the Fengtian clique's leader commanded Li to hold up the Guominjun for as long as possible.

Having inflicted heavy casualties on the Guominjun, the Zhili Army managed to retreat largely intact in good order[16] to Shandong, which was held by Li's old ally Zhang Zongchang.

Though professional elements remained, the Zhili Army was forced to replace casualties and expand its manpower with mostly unreliable recruits such as surrendered enemies, provincial militiamen and bandits.

This operation was opposed by a warlord alliance, known as the National Pacification Army which was led by Zhang Zuolin and whose core was formed by the Fengtian clique.

This was because the local National Pacification Army-affiliated warlord Sun Chuanfang was threatened to be overwhelmed by the NRA, and asked Zhang Zongchang to aid him in defending Nanjing and Shanghai.

[25] The Zhili Army under Chu was next sent against Lanfeng, where it overran the NRA on 17 October and thus made it possible for the warlord alliance to strike against Henan.

The fighting at Kaifeng soon turned against the Zhili Army which was without support, exhausted, and even betrayed by Shanxi troops who switched sides during the battle.

A counter-offensive by Feng overwhelmed Chu's army in early November, forcing it to retreat east of Shangqiu, where the front stabilized.

[26] Zhang wanted to defeat Feng before he was able to join up with the NRA units that attacked Xuzhou from Nanjing, but this preventive strike resulted in disaster.

The remnants of the Zhili Army under Chu Yupu also took part in this operation, and began to attack the NRA positions east of Daming on 6 April.

The following mass retreat of the National Pacification Army led to the fall of Shandong to the Nationalists and the effective end of the war.

[34] As result, these ex-soldiers were willing to join a rebellion instigated by Zhang Zongchang and Chu Yupu against Liu Zhennian, ruler of northeastern Shandong, in 1929.

Besieged by government forces, Chu's men committed numerous atrocities, including mass rapes and using civilians as human shields.

After 13 days, the town surrendered, and many of the surviving warlord soldiers were put to death by vengeful NRA troops and local civilians.